Hepatitis C virus persistence in human hematopoietic cells injected into SCID mice

Hepatitis Virus-associated Non-hodgkin Lymphoma: Pathogenesis and Treatment Strategies

Over the last decade, epidemiological studies have discovered a link between hepatitis C virus (HCV) and hepatitis B virus (HBV) infection and non-Hodgkin lymphoma (NHL). The regression of HCV-associated NHL after HCV eradication is the most compelling proof supporting HCV infection's role in lymphoproliferative diseases. HBV infection was found to significantly enhance the incidence of NHL, according to the epidemiological data. The exact mechanism of HCV leading to NHL has not been fully clarified, and there are mainly the following possible mechanisms: (1) Indirect mechanisms: stimulation of B lymphocytes by extracellular HCV and cytokines; (2) Direct mechanisms: oncogenic effects mediated by intracellular HCV proteins; (3) hit-and-run mechanism: permanent genetic B lymphocytes damage by the transitional entry of HCV. The specific role of HBV in the occurrence of NHL is still unclear, and the research on its mechanism is less extensively explored than HCV, and there are mainly the following possible mechanisms: (1) Indirect mechanisms: stimulation of B lymphocytes by extracellular HBV; (2) Direct mechanisms: oncogenic effects mediated by intracellular HBV DNA. In fact, it is reasonable to consider direct-acting antivirals (DAAs) as first-line therapy for indolent HCV-associated B-NHL patients who do not require immediate chemotherapy. Chemotherapy for NHL is affected by HBV infection and replication. At the same time, chemotherapy can also activate HBV replication. Following recent guidelines, all patients with HBsAg positive/HBV DNA≥2,000 IU/mL should be treated for HBV. The data on epidemiology, interventional studies, and molecular mechanisms of HCV and HBV-associated B-NHL are systematically summarized in this review.

Heterogeneity and coexistence of oncogenic mechanisms involved in HCV-associated B-cell lymphomas

The association of HCV-infection with B-lymphomas is supported by the regression of most indolent/low-grade lymphomas following anti-viral therapy. Studies on direct and indirect oncogenic mechanisms have elucidated the pathogenesis of HCV-associated B-lymphoma subtypes. These include B-lymphocyte proliferation and sustained clonal expansion by HCV-envelope protein stimulation of B-cell receptors, and prolonged HCV-infected B-cell growth by overexpression of an anti-apoptotic BCL-2 oncogene caused by the increased frequency of t(14;18) chromosomal translocations in follicular lymphomas. HCV has been implicated in lymphomagenesis by a "hit-and-run" mechanism, inducing enhanced mutation rate in immunoglobulins and anti-oncogenes favoring immune escape, due to permanent genetic damage by double-strand DNA-breaks. More direct oncogenic mechanisms have been identified in cytokines and chemokines in relation to NS3 and Core expression, particularly in diffuse large B-cell lymphoma. By reviewing genetic alterations and disrupted signaling pathways, we intend to highlight how mutually non-contrasting mechanisms cooperate with environmental factors toward progression of HCV-lymphoma.

Considering hepatitis C virus infection as a systemic disease

Hepatitis C virus (HCV) infection has been demonstrated to result in several adverse hepatic outcomes and has been associated with a number of important extrahepatic manifestations. The scope of extrahepatic clinical possibilities includes systemic diseases such as vasculitis and lymphoproliferative disorders, cardiovascular disease, myalgia, arthritis, and sicca syndrome. These end-organ effects of HCV may dominate the clinical course beyond the hepatic complications and significantly worsen the long-term prognosis of infected patients. Until several years ago, the standard of care for the treatment of HCV infection had been interferon-alpha-based regimens, which not only had limited effectiveness in achieving a cure but were often poorly tolerated, especially in patients with kidney disease. In those HCV-infected patients with significant systemic manifestations, the interferon-based regimens were problematic given their association with a wide variety of toxicities. The development of highly effective direct-acting antiviral agents to treat HCV infection presented an opportunity to improve the HCV care cascade with the eradication of HCV in most infected patients and by reducing the burden of both hepatic and extrahepatic complications.

Risk of Onset of Hematological Malignancies in Patients Infected with the Hepatitis B Virus: Results from a Large-Scale Retrospective Cohort Study in China

The hepatitis B virus (HBV) is a major global issue, because an increased risk of hepatocellular carcinoma among patients infected with HBV is well established. Recently, it has been suggested that HBV is associated with other human cancers. However, the association between HBV and the risk of onset of hematological malignancies remains controversial. The aim of this large-scale retrospective cohort study was to evaluate the association between HBV infection and hematological malignancies. A retrospective analysis of 86,115 newly admitted patients at Shanghai Ruijin Hospital was performed. A cohort of patients previously exposed to HBV (n = 1,874) and a cohort of individuals without a positive test for anti-hepatitis B core antigen (anti-HBc; n = 45,118) were compared to assess the risk of hematological malignancies. Anti-HBc was positive in 61.2% cases and 54.3% controls (p = 0.0001). The risk of B cell non-Hodgkin's lymphoma, acute lymphoblastic leukemia, and multiple myeloma was higher in the HBV-infected cohort than in the non-HBV-infected cohort. In conclusion, patients infected with HBV have a substantially increased risk of hematological malignancies.

New insights into HCV-related rheumatologic disorders: A review

Hepatitis C virus (HCV) infected patients are known to be exposed to major liver complications i.e. cirrhosis and hepatocellular carcinoma. In addition, many extrahepatic manifestations including rheumatologic disorders have been reported in up to two-third of HCV infected patients. These manifestations include frank auto-immune and rheumatic diseases (such as arthralgia, myalgia, arthritis, sicca syndrome and vasculitis) which may dominate the course of infection. Until recently, the standard of care of HCV has been the use of interferon-alpha based regimens, which not only had limited effectiveness in HCV cure but were poorly tolerated. In patients with rheumatic diseases interferon-based regimens may be problematic given their association with a wide variety of autoimmune toxicities. Recent therapeutic advances with new direct anti-HCV therapies (interferon-free) which are more effective and better tolerated, make screening for this comorbidity in patients with rheumatic disorders more important than ever. This review aimed to outline main HCV extrahepatic with a special focus on rheumatologic manifestations.

Extrahepatic manifestations of chronic hepatitis C virus infection

During hepatitis C virus (HCV) chronic infection, extrahepatic manifestations are frequent and polymorphous. This article reports on a large cohort of patients with HCV-related autoimmune or lymphoproliferative disorders, from mixed cryoglobulinemia vasculitis to frank lymphomas. The relationship between HCV infection and such immune-related diseases has been formally demonstrated by epidemiological, clinical, immunological and pathological data, and results of therapeutic trials. More recently, other nonliver-related HCV disorders have been reported, including cardiovascular (i.e. stroke, ischemic heart disease), renal, metabolic and central nervous system diseases. For these manifestations, most evidence comes from large epidemiological studies; there is a need for mechanistic studies and therapeutic trials for confirmation. Beyond the risk of developing liver complications, that is, cirrhosis and liver cancer, patients with HCV infection have an increased risk of morbidity and mortality related to nonliver diseases. HCV chronic infection should be analyzed as a systemic disease in which extrahepatic consequences increase the weight of its pathological burden. The need for effective viral eradication measures is underlined.

Virus-driven autoimmunity and lymphoproliferation: the example of HCV infection

HCV chronic infection is characterized by possible development of both hepatic and extrahepatic manifestations. The infection by this both hepatotropic and lymphotropic virus is responsible for polyoligoclonal B-lymphocyte expansion, leading to several immune-mediated disorders. Mixed cryoglobulinemia syndrome that in some cases may evolve to frank B-cell non-Hodgkin's lymphoma is the prototype of HCV-driven autoimmune and lymphoproliferative disorders. The HCV oncogenic potential has been suggested by several clinicoepidemiological and laboratory studies; it includes hepatocellular carcinoma, B-cell non-Hodgkin's lymphoma and papillary thyroid cancer. The definition HCV syndrome refers to the complex of HCV-driven diseases; these latter are characterized by heterogeneous geographical distribution, suggesting a role of other important genetic and/or environmental cofactors. The natural history of HCV syndrome is the result of a multifactorial and multistep pathogenetic process, which may evolve from mild manifestations to systemic autoimmune disorders, and less frequently to malignant neoplasias. The present updated review analyzes the clinical and pathogenetic aspects of the main HCV-associated diseases.

Extrahepatic manifestations of chronic hepatitis C virus infection

Hepatitis C virus (HCV) infected patients are known to be at risk of developing liver complications i.e. cirrhosis and liver cancer. However, the risks of morbidity and mortality are underestimated because they do not take into account non-liver consequences of chronic hepatitis C virus infection. Numerous extrahepatic manifestations have been reported in up to 74% of patients, from perceived to disabling conditions. The majority of data concern hepatitis C virus-related autoimmune and/or lymphoproliferative disorders, from mixed cryoglobulinaemia vasculitis to frank lymphomas. More recently, other hepatitis C virus-associated disorders have been reported including cardiovascular, renal, metabolic, and central nervous system diseases. This review aims to outline most of the extrahepatic manifestations that are currently being investigated, including some of autoimmune and/or lymphoproliferative nature, and others in which the role of immune mechanisms appears less clear. Beyond the liver, hepatitis C virus chronic infection should be analyzed as a multifaceted systemic disease leading to heavy direct and indirect costs. The accurate consideration of extrahepatic consequences of such a systemic infection significantly increases the weight of its pathological burden. The need for effective viral eradication measures is underlined.

Association between infection of hepatitis B virus and onset risk of B-cell non-Hodgkin's lymphoma: a systematic review and a meta-analysis

Whether an association between hepatitis B virus (HBV) infection and B-cell non-Hodgkin's lymphoma (B-NHL) risk exists is an open question. In order to provide quantification of the issue, we carried out a meta-analysis of the published data. We identified 4 case-control and 2 nested case-control studies, including a total of 5,396 B-NHL cases. We derived meta-analytic estimates using random-effects models, taking into account the correlation between estimates. The odds radio (OR) of HBV infection in B-NHL when compared with the control population was 2.98 [95 % confidence interval (CI) 2.30-3.86]. There was evidence of statistical heterogeneity among all included studies (I (2) = 65 %, P = 0.01), which disappeared in the subgroup nested case-control studies (I (2) = 0 %, P = 0.49). OR was 2.59 (95 % CI 2.03-3.30) in the random effect model, suggesting a higher prevalence of HBV carrier state in B-NHL than controls. This meta-analysis provides quantitative evidence of a favorable role of HBV infection on B-NHL risk, which needs to be confirmed by experimental and epidemiological studies.

Cellular activation and intracellular HCV load in peripheral blood monocytes isolated from HCV monoinfected and HIV-HCV coinfected patients

Background

During HCV infection, the activation status of peripheral blood monocytes and its impact on HCV replication are poorly understood. We hypothesized that a modified activation of peripheral blood monocytes in HIV-HCV coinfected compared to HCV monoinfected patients may contribute to different monocytes reservoirs of HCV replication.

Methods

We performed a case-control analysis involving HCV-infected patients with and without HIV coinfection. In peripheral blood mononuclear cells (PBMCs), peripheral blood lymphocytes (PBLs) and peripheral blood monocytes isolated from HCV monoinfected and HIV-HCV coinfected patients, intracellular HCV load and a marker of cellular activation, nuclear factor-kappaB (NF-κB) activation, were quantified using intracellular detection of HCV-core protein and electrophoretic mobility shift assay, respectively.

Results

Intracellular HCV loads were higher in monocytes isolated from HIV-HCV coinfected patients than in those of monoinfected patients. Among PBMCs isolated from HIV-HCV coinfected patients, intracellular HCV loads were higher in monocytes compared to PBLs. Cellular activation as measured by NF-κB activation was higher in monocytes isolated from HIV-HCV coinfected patients than in those of monoinfected patients.

Conclusions

Our results reveal the peripheral blood monocytes as an important extrahepatic reservoir for HCV in HIV-HCV coinfected patients and indicate a potential association between the activation state of monocytes and the size of the HCV reservoir in HIV-HCV coinfected patients.

Investigation of biomarkers in peripheral blood cells of Pakistani chronic HCV patients with genotype 3a: an assessment of HCV-induced pathogenesis

ABSTRACT: 

Aim: The main objective of the current study was to measure the mRNA expression of potent genes involved in oxidative stress, fibrosis and insulin resistance in chronic HCV patients using peripheral white blood cells. Materials & methods: A total of 50 individuals were selected for this study, including 40 chronic HCV patients and ten healthy individuals. RNA was extracted from human peripheral white blood cells of chronic HCV-infected patients and healthy individuals. Transcript analysis of selected genes was performed using real-time PCR. Results: A significant increase was observed in the mRNA expression of Nox4, TGF-β, TNF-α and collagen, while a significant decrease was observed in mRNA expression of Cu/Zn SOD and IL-10. However, there was no significant change found in mRNA expression of SOCS3 and SOCS7 level. Conclusion: The current study confirms the significant expression of different genes in peripheral white blood cells of chronic HCV patients. This could be an easy, cost-efficient approach for the assessment of HCV-induced pathologies at extrahepatic sites, which could be further validated in comparison with liver tissue biopsies.

Hepatitis viruses and non-Hodgkin’s lymphoma: A review

Non-Hodgkin’s lymphoma (NHL) is among the haematological malignancies with high prevalence worldwide, causing estimated 355 900 new cases and 191 400 deaths in 2008. High prevalence of NHL is documented in economically more developed areas while low prevalence is observed in less developed areas of the globe. A wide array of environmental factors have been reported to be either directly involved or in modifying the risk of NHL development. In addition to these factors, a number of infectious agents, chiefly viruses have also been implicated in the development of NHL. This article reviews the available literature to discuss the role of hepatitis viruses in NHL development, possible mechanisms of lymphomagenesis and also identify the areas in which further research is required to better understand this disease. A brief discussion on the clinical aspects such as classification, staging, treatment approaches have also been included in this article.

The hepatitis C virus infection as a systemic disease

Hepatitis C Virus (HCV) is a major health problem, infecting about 3 % of people worldwide and leading to liver as well as extrahepatic diseases. This justifies the definition of HCV infection as a systemic disease. Based on available data, the link between the virus and some of these extrahepatic disorders is certain, whereas for some others needs further confirmation. HCV-related lymphoproliferative disorders, ranging from benign, but pre-lymphomatous conditions, like mixed cryoglobulinemia, to frank lymphomas, represent the extrahepatic manifestations most closely related to HCV. The primary involvement of the liver and lymphatic system corresponds to the double viral tropism, being HCV able to infect both hepatic and lymphatic cells. Other HCV-associated disorders include renal, endocrine, dermatological, cardiovascular, rheumatologic and central nervous system diseases. On the whole, the HCV disease appears a very important, mainly hidden, public health problem leading to heavy direct and indirect costs. The possibility that HCV may be eradicated following antiviral therapy is important for both the therapeutic and preventive points of view, making the HCV disease an ideal model for pathogenetic studies.

Lymphoproliferative disorders in individuals with chronic hepatitis B and C in the Turkish population

The aims of this cohort study were to evaluate the association of malignant lymphoproliferative disorders in patients with chronic viral hepatitis and to compare the results with those in individuals with non-alcoholic fatty liver disease. A total of 3,873 patients with chronic liver disease who were seen consecutively in the Liver Disease Outpatient Clinic between January 2001 and July 2007 were assessed retrospectively. The frequency of malignant lymphoproliferative disorders including non-Hodgkin's lymphoma, Hodgkin's lymphoma, and chronic lymphocytic leukemia in these patients was investigated. Of the total, 1,999 patients had chronic hepatitis B infection (male/female: 1,226/773, mean age: 45.1 ± 13.2 years), 978 had chronic hepatitis C infection (male/female: 437/541, mean age: 53.8 ± 13.7 years), and the remaining 896 had non-alcoholic fatty liver disease (male/female: 450/446, mean age: 50.8 ± 11.2 years). A malignant lymphoproliferative disorder was identified in 13 patients (male/female: 9/4, mean age: 52.8 ± 16.8 years) with chronic viral hepatitis, while no case of malignant lymphoproliferative disorder was identified in individuals with non-alcoholic fatty liver disease (P = 0.048). Among the patients with malignant lymphoproliferative disorders, seven had chronic hepatitis B infection and six had chronic hepatitis C infection; 11 had non-Hodgkin's lymphoma and two had chronic lymphocytic leukemia. All non-Hodgkin's lymphoma cases were B-cell lymphoma. Based on the data obtained in this investigation, the association with malignant lymphoproliferative disorders in chronic viral hepatitis seems to be high as compared to that occurring in individuals with non-alcoholic fatty liver disease.

Hepatitis C virus infection in the immunocompromised host: a complex scenario with variable clinical impact

The relationship between Hepatitis C Virus (HCV) infection and immunosuppression is complex and multifaceted. Although HCV-related hepatocytolysis is classically interpreted as secondary to the attack by cytotoxic T lymphocytes against infected cells, the liver disease is usually exacerbated and more rapidly evolutive in immunosuppressed patients. This generally occurs during the immunosuppression state, and not at the reconstitution of the host response after immunosuppressive therapy discontinuation. The field of immunosuppression and HCV infection is complicated both by the different outcome observed in different situations and/or by contrasting data obtained in the same conditions, with several still unanswered questions, such as the opportunity to modify treatment schedules in the setting of post-transplant follow-up. The complexity of this field is further complicated by the intrinsic tendency of HCV infection in itself to lead to disorders of the immune system. This review will briefly outline the current knowledge about the pathogenesis of both hepatic and extrahepatic HCV-related disorders and the principal available data concerning HCV infection in a condition of impairment of the immune system. Attention will be especially focused on some conditions - liver or kidney transplantation, the use of biologic drugs and cancer chemotherapy - for which more abundant and interesting data exist.

HCV and lymphoproliferation

Hepatitis C virus (HCV) infection is a serious public health problem because of its worldwide diffusion and sequelae. It is not only a hepatotropic but also a lymphotropic agent and is responsible not only for liver injury--potentially evolving to cirrhosis and hepatocellular carcinoma--but also for a series of sometimes severely disabling extrahepatic diseases and, in particular, B-cell lymphoproliferative disorders. These latter range from benign, but prelymphomatous conditions, like mixed cryoglobulinemia, to frank lymphomas. Analogously with Helicobacter pylori related lymphomagenesis, the study of the effects of viral eradication confirmed the etiopathogenetic role of HCV and showed it is an ideal model for better understanding of the molecular mechanisms involved. Concerning these latter, several hypotheses have been proposed over the past two decades which are not mutually exclusive. These hypotheses have variously emphasized the important role played by sustained stimulation of the immune system by HCV, infection of the lymphatic cells, viral proteins, chromosomal aberrations, cytokines, or microRNA molecules. In this paper we describe the main hypotheses that have been proposed with the corresponding principal supporting data.

Presence of plus-strand HCV RNA in serum and PBMCs as an indicator for relapse and resistance to IFN therapy in patients infected by HCV

Aim: The aim of our study was to investigate the correlation between the presence of plus-/minus-strand HCV RNA in peripheral blood mononuclear cells (PBMCs) and serum following pegylated IFN/ribavirin therapy with response to therapy in HCV-infected patients. Methods: Forty-three HCV-infected patients who completed 48 weeks of IFN/ribavirin therapy, including 25 sustained virologic responders, 12 resistants and six relapsers, comprised the study population. Plus-/minus-strand HCV RNA was detected by reverse transcription PCR in serum and PBMCs. Results: The frequency of plus-strand HCV RNA was significantly higher in PBMC and serum samples of relapsers and resistants, and this might have important implications in clinical practice and patient management. There was no correlation between presence of plus- and minus-strand HCV RNA and genotypes, except the fact that most of the patients who had plus-strand HCV RNA in PBMCs (60%) and in serum (61.53%) belonged to genotype 1a. Conclusion: Presence of plus-strand HCV RNA in PBMCs and serum after termination of therapy is associated with viral relapse and resistance to IFN/ribavirin treatment in HCV-infected patients.

Hepatitis viruses and non-Hodgkin lymphoma: epidemiology, mechanisms of tumorigenesis, and therapeutic opportunities

Over the past 2 decades considerable evidence has accumulated on the association between hepatitis C virus (HCV) and hepatitis B virus (HBV) and several hematologic malignancies, most notably B-cell non-Hodgkin lymphoma (NHL). In this review we summarize this evidence, address possible mechanisms whereby hepatitis viruses may contribute to lymphomagenesis, and discuss the therapeutic fallouts from this knowledge. Most of this evidence is on HCV, and this is the main focus of the review. Moreover, we mainly address the association with NHL, the most prevalent hematologic malignancy, and the most extensively investigated with regard to an association with hepatitis viruses. Available evidence on the association with other hematologic malignancies is also addressed briefly.

Hepatitis C virus and peripheral blood mononuclear cell reservoirs Patricia Baré

The existence of hepatitis C virus (HCV) infection in extrahepatic sites has been widely demonstrated. Since peripheral blood mononuclear cells have been the most investigated, compelling evidence of an association with HCV has been shown. Different studies have revealed that HCV RNA can persist and replicate in immune cells but the relevance of its presence and persistence over time is still unknown. As the contribution of this extrahepatic reservoir could have several clinical implications in viral transmission, treatment response and disease pathogenesis, future studies are required to improve our knowledge of the extrahepatic manifestations of HCV and its possible consequences.

Hepatitis C virus quasispecies in plasma and peripheral blood mononuclear cells of treatment naïve chronically infected patients

Peripheral blood mononuclear cells (PBMCs) from 45 treatment naïve, HIV-negative, chronically hepatitis C virus (HCV)-infected patients were analyzed for the presence of HCV RNA. Viral RNA was detected in 73% of the studied patients. Single-strand conformation polymorphism assays and sequence analysis of the HCV 5'untranslated regions amplified from RNA recovered from both Plasma and PBMCs suggested virus compartmentalization in 57.6% of patients studied. In summary, our study presents evidence that HCV RNA can be found in PBMCs of treatment naïve chronically infected patients that are not immunocompromised or co-infected with the human immunodeficiency virus.

Molecular and contextual markers of hepatitis C virus and drug abuse

The spread of hepatitis C virus (HCV) infection involves a complex interplay of social risks, and molecular factors of both virus and host. Injection drug abuse is the most powerful risk factor for HCV infection, followed by sexual transmission and additional non-injection drug abuse factors such as co-infection with other viruses and barriers to treatment. It is clearly important to understand the wider context in which the factors related to HCV infection occur. This understanding is required for a comprehensive approach leading to the successful prevention, diagnosis, and treatment of HCV. An additional consideration is that current treatments and advanced molecular methods are generally unavailable to socially disadvantaged patients. Thus, the recognition of behavioral/social, viral, and host factors as components of an integrated approach to HCV is important to help this vulnerable group. Equally important, this approach is key to the development of personalized patient treatment - a significant goal in global healthcare. In this review, we discuss recent findings concerning the impact of drug abuse, epidemiology, social behavior, virology, immunopathology, and genetics on HCV infection and the course of disease.

Extrahepatic manifestations of hepatitis C virus infection

Hepatitis C virus may cause hepatic and extrahepatic diseases. Extrahepatic manifestations range from disorders for which a significant association with viral infection is supported by epidemiologic and pathogenetic data, to anecdotal observations without clear proof of causality. This article describes the diagnosis and treatment of these diseases.

Hepatitis C viral kinetics in plasma and peripheral blood mononuclear cells during pegylated interferon-alpha2a/ribavirin therapy

BACKGROUND/AIMS

Analysis of hepatitis C virus (HCV) RNA kinetics in compartments other than plasma may help in understanding HCV replication and identifying clinically significant patterns of treatment response.

METHODS

After 6 weeks of pegylated interferon-alpha2a/ribavirin therapy, 74 chronic hepatitis C patients were randomized to individualized or standard treatments for another 42 weeks. HCV RNA was quantified in peripheral blood mononuclear cells (PBMCs) by TaqMan-based real-time PCR and compared to plasma HCV RNA.

RESULTS

HCV RNA declines in PBMCs and plasma were comparable during the initial 12 weeks of therapy (Spearman's rank correlation range over different time points, 0.73-0.97). However, a delay of HCV RNA decay in PBMCs, expected if kinetics in PBMCs only reflected kinetics in plasma, was rarely observed. For many patients, HCV RNA decline in PBMCs started as early as in plasma and for some of them the kinetics strongly differed in the two compartments, hinting at a compartment-specific HCV replication and treatment effect. Fast viral decay in PBMCs was associated with sustained virological response, but viral kinetics in PBMCs added only minor predictive information compared with kinetics in plasma.

CONCLUSIONS

Future kinetics studies of HCV RNA during therapy with new antivirals should take into account their compartment-specific effect.

Hepatitis C virus lymphotropism: lessons from a decade of studies

The possibility that HCV infects lymphoid cells has been widely discussed. Evidence in favor of HCV tropism for lymphoid cells derives from a series of data including: (1) the higher sensitivity of testing HCVRNA in PBMC than in serum or plasma samples, with possible detection of HCV RNA-positive PBMC in the absence of HCV viremia; (2) short-term cultures of PBMC which yield a significant increase in the amount of viral RNA on stimulation by mitogens; (3) results of "in situ" methods (i.e. in situ hybridization, immunofluorescence); (4) efficient infection of lymphoid cell lines or PBMC from normal individuals; (5) the persistence of HCV RNA in PBMC obtained from HCV-positive subjects and injected into SCID mice; (6) the long-term persistence of HCV RNA in PBMC in spite of HCV RNA negativity of serum and liver in sustained responder patients after therapy. The principal criticisms concerning effective HCV infection of lymphoid cells arise from technical difficulty in identifying HCV RNA replicative intermediate in these elements. Conflicting data may also result from differences in PBMC infection by different genotypes, samples taken at different stages in the disease process and differences in the sensitivity of detection methods, as well as low replication levels and/or proportion of infected PBMC. Interesting available data about HCV lymphotropism, which is possibly important in influencing the natural history of infection, include: (1) possible preferential viral tropism for specific PBMC subsets; (2) different lymphotropism of different viral strains; (3) selection of distinctive viral strains; (4) identification of putative HCV cell receptors; (5) association between determination of HCV lymphatic infection and t(14; 18) translocation. The clinical correlates of HCV lymphotropism are potentially very numerous, including, first, its role in determining HCV-related lymphoproliferative disorders.

HCV infection facilitates asymptomatic carotid atherosclerosis: preliminary report of HCV RNA localization in human carotid plaques

BACKGROUND

Clinical and experimental evidence suggests that hepatitis C virus (HCV) infection shows peculiar characteristics that strongly support a role in the development of atherosclerosis. We aimed to investigate whether (a) HCV infection can facilitate asymptomatic carotid lesions and (b) the presence of HCV RNA sequences can be shown in plaque tissues.

METHODS

The status of carotid arteries, studied as intima-media thickness (IMT) in carotid bifurcation and prevalence and severity of plaques in internal carotid artery, was investigated by high-resolution B-mode ultrasonography in 31 HCV seropositive (HCV+) and in 120 age-matched HCV seronegative (HCV-) subjects evaluated for cardiovascular risk factors. The atherosclerotic risk profile, inflammation markers and main liver function tests were also studied in all patients. HCV RNA sequences were investigated by highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) in plaque tissues and serum of 2 HCV+ patients who underwent carotid revascularization.

RESULTS

Genomic and antigenomic HCV RNA strands were evidenced within both the carotid plaque tissues examined. The prevalence of an IMT > 1 mm, but not the prevalence and severity of internal carotid plaques, was significantly higher (P < 0.001) in HCV+ than in HCV patients. The atherosclerotic risk profile for traditional and inflammatory factors did not differ between the HCV+ and HCV- groups. Main liver function tests did not differ between the two groups. HCV positivity was significantly associated with >1 mm IMT (P < 0.01) according to univariate analysis, and this association remained significant in multivariate regression analysis.

CONCLUSIONS

The novel finding of HCV RNA sequences within carotid plaques suggests a local pro-atherogenetic action of the virus inside the plaque. On the whole our data strongly support that HCV infection facilitates the occurrence of carotid atherosclerotic lesions.

Hepatitis C virus-related lymphoproliferative disorders: An overview

Hepatitis C virus (HCV) is a global health problem affecting 3% of the world's population (about 180 million) and a cause of both hepatic and extrahepatic diseases. B-cell lymphoproliferative disorders, whose prototype is mixed cryoglobulinemia, represent the most closely related as well as the most investigated HCV-related extrahepatic disorder. The association between extrahepatic (lymphoma) as well as hepatic malignancies (hepatocellular carcinoma) has justified the inclusion of HCV among human cancer viruses. HCV-associated manifestations also include porphyria cutanea tarda, lichen planus, nephropathies, thyreopathies, sicca syndrome, idiopathic pulmonary fibrosis, diabetes, chronic polyarthritis, sexual dysfunctions, cardiopathy/atherosclerosis, and psychopathological disorders. A pathogenetic link between HCV virus and some lymphoproliferative disorders was confirmed by their responsiveness to antiviral therapy, which is now considered the first choice treatment. The aim of the present paper is to provide an overview of extrahepatic manifestations of HCV infection with particular attention to B-cell lymphoproliferative disorders. Available pathogenetic hypotheses and suggestions about the most appropriate, currently available, therapeutic approaches will also be discussed.

Bone marrow cells: the source of hepatocellular carcinoma?

Whether the stem cells or the mature cells are the origination of hepatocellular carcinoma is uncertain. Recently, researches have shown that some cancer stem cells could derive from adult stem cells. Moreover, gastric cancer could originate from bone marrow stem cells. Hematopoiesis and the hepatic environment are known to have a close relationship at the time of hepatic development and systemic diseases. Here we propose a new carcinogenetic model of hepatocellular carcinoma. Chronic liver injury could recruit bone marrow stem cells to the liver. Bone marrow cells take part in liver regeneration by differentiating to oval cells and hepatocytes. Persistent regeneration results in hyperproliferation, an increased rate of transforming mutations. Extracellular matrix remodeling triggers a cascade of events that inhibits the transactivation potential of liver-specific transcription factors, blocks the maturation of stem cells, and then results in hepatocellular carcinoma.

Host and viral factors in the immunopathogenesis of primary hepatitis C virus infection

Individuals infected with hepatitis C virus (HCV) have two possible outcomes of infection, clearance or persistent infection. The focus of this review is the host mechanisms that facilitate clearance. The interaction between HCV viral components and the immune system ultimately determines the balance between the virus and host. Strong evidence points to the aspects of cellular immune response as the key determinants of outcome. The recent discovery of viral evasion strategies targeting innate immunity suggests that the interferon-alpha/beta induction pathways are also critical. A growing body of evidence has implicated polymorphisms in both innate and adaptive immune response genes as determinants of viral clearance in individuals infected with HCV.

Negative-strand hepatitis C virus (HCV) RNA in peripheral blood mononuclear cells from anti-HCV-positive/HIV-infected women

BACKGROUND

Hepatitis C virus (HCV) has been reported to replicate in peripheral blood mononuclear cells (PBMCs), particularly in patients coinfected with HCV and human immunodeficiency virus (HIV). However, there are limited data regarding the prevalence of and the factors associated with extrahepatic replication.

METHODS

The presence of negative-strand HCV RNA in PBMCs was evaluated by a strand-specific assay for 144 anti-HCV-positive/HIV-infected women enrolled in the Women's Interagency HIV Study. One to 5 PBMC samples obtained from each woman were tested. Multivariate analyses were used to assess for associations with the clinical and demographic characteristics of the women.

RESULTS

Negative-strand HCV RNA was detected in 78 (25%) of 315 specimens, and, for 61 women (42%), > or = 1 specimen was found to have positive results. The presence of negative-strand HCV RNA in PBMCs was significantly positively associated with an HCV RNA plasma level of > or = 6.75 log copies/mL (P=.04) and consumption of > or = 7 alcoholic drinks per week (P=.02). It was also negatively associated with injection drug use occurring in the past 6 months (P=.03). A negative association with a CD4+ CD38+ DR+ cell percentage of > 10% and a positive association with acquired immunodeficiency syndrome were borderline significant (P=.05).

CONCLUSIONS

HCV replication in PBMCs is common among HIV-coinfected women and appears to be a dynamic process related to lifestyle, virologic, and immunologic factors.

Protective immunity against hepatitis C virus infection

There is increasing evidence that a small percentage of individuals exposed to the hepatitis C virus have the capacity to generate a strong cellular immune response against the virus and avoid persistent infection, and perhaps do so repeatedly after re-exposure. This article reviews the evidence that the responses identified in this unique group of individuals represent the protective immunity that will need to be elicited by hepatitis C virus vaccines.

Fas ligand is responsible for CXCR3 chemokine induction in CD4+ T cell-dependent liver damage

Immune-mediated hepatic damage has been demonstrated in the pathogenesis of hepatitis C virus (HCV) and other hepatotrophic infections. Fas/Fas ligand (FasL) interaction plays a critical role in immune-mediated hepatic damage. To understand the molecular mechanism(s) of FasL-mediated liver inflammation, we examined the effect of CD4(+) T cells expressing high levels of FasL on the initiation of hepatic damage through analysis of chemokine and chemokine receptor expression in HCV core x TCR (DO11.10) double-transgenic mice. In vivo antigenic stimulation triggers a marked influx of core-expressing Ag-specific CD4(+) T cells into the liver of the immunized core(+) TCR mice but not their core(-) TCR littermates. Strikingly, the inflammatory process in the liver of core(+) TCR mice was accompanied by a dramatic increase in IFN-inducible protein 10 and monokine induced by IFN-gamma production. The intrahepatic lymphocytes were primarily CXCR3-positive and anti-CXCR3 Ab treatment abrogates migration of CXCR3(+) lymphocytes into the liver and hepatic damage. Importantly, the blockade of Fas/FasL interaction reduces the expression of IFN-inducible protein 10 and monokine induced by IFN-gamma and cellular infiltration into the liver. These findings suggest that activated CD4(+) T cells with elevated FasL expression are involved in promoting liver inflammation and hepatic damage through the induction of chemokines.

Real-time multiplex PCR assay to quantify hepatitis C virus RNA in peripheral blood mononuclear cells

Ultrasensitive methods to measure very low levels of hepatitis C virus (HCV) RNA in biological samples may have diagnostic and prognostic significance and be useful to evaluate the response to antiviral treatment. A sensitive assay to quantify HCV RNA in peripheral blood mononuclear cells (PBMCs) was developed and validated using the iCycler iQ Detection System (Bio-Rad) coupled with TaqMan chemistry. HCV was co-amplified with the endogenous control glyceraldehyde-3-phosphate dehydrogenase in a multiplex reaction. Calculated PCR amplification efficiencies for both target and control genes were used in a mathematical model for relative quantitation of HCV RNA. A linear relationship between input RNA and C(T) values over 6 log dilutions was observed for both HCV- and GAPDH-specific products (R(2) > or = 0.99). As few as 1.5 IU/reaction could be detected, with high accuracy (CV < or= 3.94%) and reproducibility (CV < or = 2.20%). Quantitation of HCV RNA levels ranging from 10(3) to 10(7) IU/ml as measured in 47 plasma samples was highly correlated with values obtained by the COBAS Amplicor HCV Monitor test, v2.0 (Roche) (R(2) = 0.977). In conclusion, this assay provides an excellent tool to determine accurately HCV kinetics in PBMCs during antiviral therapy and to assess the long-term significance of different patterns of response to treatment.

Emerging evidence of hepatitis C virus neuroinvasion

It has been reported that hepatitis C virus (HCV) infection is associated with cognitive dysfunction, fatigue and depression, which do not correlate with the severity of liver disease and cannot be accounted for by hepatic encephalopathy or drug abuse. There is also emerging evidence that HCV infection can have negative neurocognitive effects in HIV-infected cohorts. Magnetic resonance spectroscopy has suggested the likely existence of a biological basis for these effects. HCV replicative forms have recently been detected in autopsy brain tissue and the infected cells have been identified as CD68-positive (macrophages/microglia). These findings raise the possibility that HCV infection of the brain could be directly related to the reported neuropsychological and cognitive changes. HCV is not strictly hepatotropic, as it can also replicate in leukocytes, including monocytes/macrophages. The latter cells could provide access of HCV into the central nervous system ('Trojan horse' mechanism) in a process similar to that postulated for HIV-1. In support of this hypothetical mechanism come reports showing a close relationship between HCV sequences present in the brain and cerebrospinal fluid and sequences found in lymph nodes and peripheral blood mononuclear cells. However, despite some similarities there is a fundamental difference between HIV-1 and HCV infection as the latter does not progress into AIDS-type dementia.

Hepatitis C virus core protein induces an anergic state characterized by decreased interleukin-2 production and perturbation of mitogen-activated protein kinase responses

Alterations of cytokine responses are thought to favor the establishment of persistent hepatitis C virus (HCV) infections, enhancing the risk of liver cirrhosis and hepatocellular carcinoma. Here we demonstrate that the expression of the HCV core (C) protein in stably transfected T cells correlates with a selective reduction of interleukin-2 (IL-2) promoter activity and IL-2 production in response to T-cell receptor triggering, whereas the activation of IL-4, IL-10, gamma interferon, and tumor necrosis factor alpha was moderately increased. This altered cytokine expression profile was associated with a perturbation of mitogen-activated protein (MAP) kinase responses. Extracellular regulated kinase and p38 were constitutively phosphorylated in C-expressing cells, while triggering of the costimulatory c-Jun N-terminal kinase (JNK) signaling cascade and activation of the CD28 response element within the IL-2 promoter appeared to be impaired. The perturbations of MAP kinase phosphorylation could be eliminated by cyclosporine A-mediated inhibition of nuclear factor of activated T cells, suggesting that the inactivation of JNK signaling and hyporesponsiveness to IL-2 induction were downstream consequences of C-induced Ca(2+) flux in a manner that mimics the induction of clonal anergy.

Compartmentalization of hepatitis C virus genotypes between plasma and peripheral blood mononuclear cells

Differences in hepatitis C virus (HCV) variants of the highly conserved 5' untranslated region (UTR) have been observed between plasma and peripheral blood mononuclear cells (PBMC). The prevalence and the mechanisms of this compartmentalization are unknown. Plasma and PBMC HCV variants were compared by single-strand conformation polymorphism (SSCP) and by cloning or by genotyping with a line probe assay (LiPA) in 116 chronically infected patients, including 44 liver transplant recipients. SSCP patterns differed between compartments in 43/109 analyzable patients (39%). Differences were significantly more frequent in patients with transplants (21/38 [55%] versus 22/71 [31%]; P < 0.01) and in those who acquired HCV through multiple transfusions before 1991 (15/20; 75%) or through drug injection (16/31; 52%) than in those infected through an unknown route (7/29; 24%) or through a single transfusion (5/29; 17%; P < 0.001). Cloning of the 5' UTR, LiPA analysis, and nonstructural region 5B sequencing revealed different genotypes in the two compartments from 10 patients (9%). In nine patients, the genotype detected in PBMC was not detected in plasma and was weak or undetectable in the liver in three cases. This genotypic compartmentalization persisted for years in three patients and after liver transplantation in two. The present study shows that a significant proportion of HCV-infected subjects harbor in their PBMC highly divergent variants which were likely acquired through superinfections.

Increased Fas ligand expression of CD4+ T cells by HCV core induces T cell-dependent hepatic inflammation

Hepatitis C virus (HCV) infection is associated with a high rate of viral persistence and the development of chronic liver disease. The expression of HCV core protein in T cells has previously been reported to alter T cell activation and has been linked to the development of liver inflammation. However, the molecular and cellular basis for the role of HCV core-expressing T cells in liver inflammation is not understood. Here, using double-transgenic mice of CD2/HCV-core transgenic mice and ovalbumin (OVA)-specific T cell receptor transgenic mice, we demonstrated that in vivo antigenic stimulation (OVA peptide administration) triggers a marked influx of core-expressing, antigen-specific, transgenic CD4+ T cells into the liver of these mice. Phenotypic analysis of the liver-infiltrating T cells revealed high expression levels of CD44 and Fas ligand (FasL). Adoptive transfer of liver-infiltrating, core-expressing CD4+ T cells into severe combined immunodeficiency mice directly demonstrated the capacity of these activated T cells to induce liver inflammation. It is important that anti-FasL antibody treatment of the mice at the time of cell transfer abrogated the liver inflammation induced by core-expressing CD4+ T cells. These findings suggest that activated T lymphocytes expressing elevated levels of FasL may be involved in the bystander killing of hepatocyte, as well as the induction of chronic liver inflammation, by promoting recruitment of proinflammatory cells to the liver.

Second hepatitis C replication compartment indicated by viral dynamics during liver transplantation

BACKGROUND/AIMS

The existence of an extrahepatic hepatitis C virus replication compartment is an important question for optimizing therapy and preventing the infection of liver grafts. An extraheptic replication compartment could be indicated if viral decline during the anhepatic phase is not a single exponential. However, the duration of the anhepatic phase is too short (0.5-2h) to allow such analysis. Here we mathematically analyze viral decline during liver transplantation beyond the period of the anhepatic phase and examine the possibility of viral compartmentalization.

METHODS

Viral load of 30 patients undergoing liver transplantation was frequently measured. Simulation and non-linear fitting of differential equation models were used to test different compartmentalization hypotheses.

RESULTS

In 16 of the patients (56%), a bi-phasic viral decline was observed which is explained by the existence of a second replication compartment. This extrahepatic compartment is responsible for about 3.1% of virus in circulation and the mean half-life of its infected cells is 2.6 days. The remaining patients, with a single exponential decline, have either a second compartment with relatively low contribution or no second compartment.

CONCLUSIONS

These results provide a first quantitative picture of the extrahepatic hepatitis C viral contribution and may suggest new approaches for viral clearance.

Identification of unique hepatitis C virus quasispecies in the central nervous system and comparative analysis of internal translational efficiency of brain, liver, and serum variants

Reports of cerebral dysfunction in chronic hepatitis C virus (HCV) infection have led to the suggestion that HCV may infect the central nervous system (CNS). We used reverse transcription-PCR, cloning, and sequencing to define quasispecies for the HCV internal ribosomal entry site (IRES) and hypervariable region 1 (HVR1) in autopsy-derived brain, liver, lymph node, and serum samples. There was evidence of tissue compartmentalization of sequences in the brain in two patients, with between 24 and 55% of brain-derived IRES sequences absent from the serum, and significant phylogenetic and phenetic clustering of the brain and lymph node HVR1 sequences. The IRES initiates cap-independent translation of the viral polyprotein. Two unique brain-derived IRES mutations (C(204)-->A and G(243)-->A), which have previously been associated with lymphoid replication and altered translational efficiency in cell culture, were found in one patient. We used a dicistronic reporter vector to test whether brain-derived variants showed altered IRES-mediated translational efficiency, which might favor CNS infection. The translational efficiencies of the brain-derived IRES sequences were generally reduced compared to those of the master serum and liver sequences in rabbit reticulocyte cell lysates and two human cell lines, HuH7 (liver) and CHME3 (microglial). The C(204)-->A and G(243)-->A mutations showed preserved translational efficiency in HuH7 cells but reduced efficiency in CHME3 cells. Our data provide evidence that the CNS is a site of HCV replication, consistent with the recent demonstration of negative-strand HCV RNA in brain, and suggest that IRES polymorphisms may be important as a viral strategy of reduced translation to favor latency in the CNS.

Screening of HCTP4 interacting proteins in leukocytes by yeast-two hybrid technique

AIM: To investigate the biological function of HCTP4, yeast-two hybrid was performed to screen proteins interacting with HCTP4 in leukocytes.

METHODS: The HCTP4 gene was amplified by polymerase chain reaction (PCR) and HCTP4 bait plasmid was constructed by using yeast-two hybrid system 3, then the constructed vector was transformed into yeast AH109. The transformed yeast mated with yeast Y187 containing leukocytes cDNA library plasmid in 2×YPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) and synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) containing x--gal for selecting two times and screening. After extracting and sequencing of plasmid from blue colonies, we underwent analysis by bioinformatics.

RESULTS: Forty-four colonies were sequenced, among which twenty-five colonies were immunoglobulin lambda light chain, six human DNA sequences from clone RP11-189K21, four human DNA sequences from clone RP11-507C10, two homo sapiens 12p BAC RPCI11-75L1, one homo sapiens BAC clone RP11-21M10, one homo sapiens ubiquitin ligase mind bomb (MIB), one homo sapiens genomic DNA, chromosome 11 clone: RP11-867O8, one human DNA sequence from clone RP3-509I19, one homo sapiens small nuclear ribonucleoprotein polypeptide G, one homo sapiens UMP-CMP kinase (UMP-CMPK), and a new gene.

CONCLUSION: Genes of HCTP4 interacting proteins in leukocytes are successfully cloned and the results bring some new clues for studying the biological functions of HCTP4 and associated proteins.

Infection of primary human macrophages with hepatitis C virus in vitro: induction of tumour necrosis factor-alpha and interleukin 8

Hepatitis C virus (HCV) has been reported to replicate in monocytes/macrophages in infected patients. However, it is unclear whether macrophages are susceptible to infection in vitro and whether such an infection is consequential. Sera from 26 HCV-infected patients were incubated with primary human macrophages collected from healthy donors. Virus negative strand was detected by a Tth enzyme-based strand-specific assay and virus sequences were analysed by single strand conformation polymorphism (SSCP) and sequencing. Concentrations of the cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1beta, IL-6, IL-8, IL-10 and IL-12p70 were measured in culture supernatants and respective mRNAs were analysed in cell extracts by quantitative RT-PCR. For 15 sera, HCV RNA was detectable in 2- and 3-week cultures from at least one donor. Virus negative strand was detected in 29 % of macrophage samples in this group. In four cases, HCV RNA sequences amplified from macrophages differed from those amplified from sera suggesting evolution during infection. Concentrations of TNF-alpha and IL-8 were found to be significantly higher in supernatants from HCV-infected cultures. In conclusion, these preliminary data suggest that primary human macrophages are susceptible to HCV infection in vitro and this infection is associated with the induction of cytokines TNF-alpha and IL-8.

Clinical Response of Antilymphocyte Globulin-Based Treatment in Patients in Taiwan with Aplastic Anemia: Positive Hepatitis C Antibody May Represent a Response Predictor

Immunosuppression (IS) therapy with antilymphocyte globulin (ALG) is currently the treatment of choice for patients with aplastic anemia who do not have histocompatible sibling donors or who are not candidates for allogeneic bone marrow transplantation. Thirty-eight patients with aplastic anemia who received ALG-based therapy at a single institute in Taiwan were analyzed, and 28 were followed up for more than 6 months. Four patients (10.5%) had a complete response, and 11 (28.9%) had a partial response. The overall response rate was 39.4%. The significant prognostic factor that affected the response to IS therapy was a positive test result for antibodies to the hepatitis C virus. The rate of early mortality (death within 90 days after initiation of ALG-based therapy) was 15.8%, and most deaths were secondary to infection. Factors influencing the risk of early mortality were old age, hypotension, and bacteremia. In conclusion, ALG-based IS therapy was effective for aplastic anemia in Chinese patients. The role of hepatitis C associated with aplastic anemia and its relationship to IS need to be clarified by further investigations.

Human immunodeficiency virus facilitates infection/replication of hepatitis C virus in native human macrophages

Hepatitis C virus (HCV) was found to replicate in monocytes/macrophages particularly in patients with human immunodeficiency virus type 1 (HIV-1) infection. This study was undertaken to determine whether HIV facilitates HCV infection of native human macrophages in vitro. Monocytes/macrophages were collected from healthy donors, infected with HIV M-tropic molecular clone, and then exposed to HCV-positive sera. Presence of positive and negative HCV RNA strands was determined with a novel strand-specific quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). Preceding as well as near-simultaneous infection with HIV made the macrophages more susceptible to infection with HCV; in particular, an HCV RNA-negative strand was detectable almost exclusively in the setting of concomitant HIV infection. Furthermore, HCV RNA load correlated with HIV replication level in the early stage of infection. The ratio of positive to negative strand in macrophages was lower than in control liver samples. HIV infection was also found to facilitate HCV replication in a Daudi B-cell line with engineered CD4 expression. It seems that HIV infection can facilitate replication of HCV in monocytes/macrophages either by rendering cells more susceptible to HCV infection or by increasing HCV replication. This could explain the presence of extrahepatic HCV replication in HIV-coinfected individuals.

The C-terminal region of hepatitis C core protein is required for Fas-ligand independent apoptosis in Jurkat cells by facilitating Fas oligomerization

Hepatitis C virus (HCV) is remarkable for its ability to establish persistent infection. Studies suggest that HCV core protein modulates immune responses to viral infection and can bind Fas receptor in vitro. To further examine the role of HCV core protein in Fas signaling, full-length (aa 1-192) and truncated (aa 1-152) HCV core proteins were expressed in Jurkat lymphocytes and cells were assayed for apoptotic response, caspase activation, and Fas activation. Jurkat expressing full-length but not truncated core protein exhibited ligand-independent apoptosis. Cytoplasmic targeting of truncated core protein recapitulated its ability to induce apoptosis. Activation of caspases 8 and 3 was necessary and sufficient for full-length core to induce apoptosis. Jurkat cells expressing full-length but not truncated core protein induced Fas receptor aggregation. HCV core activates apoptotic pathways in Jurkat via Fas and requires cytoplasmic localization of core. Infection of host lymphocytes by HCV may alter apoptotic signaling and skew host responses to acute infection.

Hepatitis C virus and B-cell non-Hodgkin lymphomas: an Italian multicenter case-control study

The existence of an association between infection with hepatitis C virus (HCV) and B-cell non-Hodgkin lymphoma (B-NHL) remains controversial, largely because previous studies were based on prevalent case series or comparisons with less than optimal control groups. This hospital-based case-control study was conducted from January 1998 through February 2001 to evaluate the association between HCV infection and B-NHL of different types. Cases were consecutive patients with a new diagnosis of B-NHL; controls were patients from other departments of the same hospitals. Both groups were interviewed using a standardized questionnaire. The prevalence of HCV infection was calculated by histologic type of B-NHL and clinical behavior (indolent or aggressive). Adjusted odds ratio (OR) and HCV-attributable risk (AR) were estimated. HCV prevalence was 17.5% among the 400 lymphoma patients and 5.6% among the 396 controls. The OR of B-NHL (patients vs controls), adjusted by age, sex, level of education, and place of birth, was 3.1 (95% confidence interval [CI], 1.8-5.2); an OR indicative of positive association was found for indolent and aggressive B-NHL. The estimated AR was 4.6%. This study confirms an association between HCV and B-NHL. In Italy, 1 of 20 instances of B-NHL may be attributable to HCV infection and may, thus, benefit from antiviral treatment.

The hepatitis C virus core protein modulates T cell responses by inducing spontaneous and altering T-cell receptor-triggered Ca2+ oscillations

Alterations of cytokine responses are thought to favor the establishment of persistent hepatitis C virus (HCV) infection, enhancing the risk of liver cirrhosis and hepatocellular carcinoma. Expression of the HCV core (C) protein modulates transcription of the IL-2 promoter in T lymphocytes by activating the nuclear factor of activated T lymphocyte (NFAT) pathway. Here we report on the effect of HCV C on Ca2+ signaling, which is essential for activation of NFAT. Expression of HCV C correlated with increased levels of cytosolic Ca2+ and spontaneous Ca2+ oscillations in transfected Jurkat cells. Triggering of the T-cell receptor induced a prolonged Ca2+ response characterized by vigorous high frequent oscillations in a high proportion of the responding cells. This was associated with decreased sizes and accelerated emptying of the intracellular calcium stores. The effect of HCV C on calcium mobilization was not dependent on phospholipase C-gamma 1 (PLC-gamma) activity or increased inositol 1,4,5-trisphosphate (IP3) production and did not require functional IP3 receptors, suggesting that insertion of the viral protein in the endoplasmic reticulum membrane may be sufficient to promote Ca2+ leakage with dramatic downstream consequences on the magnitude and duration of the response. Our data suggest that expression of HCV C in infected T lymphocytes may contribute to the establishment of persistent infections by inducing Ca2+ oscillations that regulate both the efficacy and information content of Ca2+ signals and are ultimately responsible for induction of gene expression and functional differentiation.

Prevalence and incidence of cryoglobulins in hepatitis C virus-related chronic hepatitis patients: a prospective study

OBJECTIVE

A high prevalence of cryoglobulins has been reported in patients with hepatitis C virus (HCV)-related liver disease. The aim of this study was to evaluate the prevalence and the incidence of cryoglobulins and their association with clinical symptoms in chronic hepatitis and cirrhosis patients.

METHODS

The prevalence of cryoglobulins and cryoglobulinemic syndrome was investigated at enrollment in 237 patients (213 with chronic hepatitis and 24 with cirrhosis). A 7-yr follow-up was conducted evaluating the occurrence of cryoglobulins and/or cryoglobulinemic syndrome every 6 months. Rheumatoid factor was also tested in all patients.

RESULTS

Prevalence of rheumatoid factor, cryoglobulins, and cryoglobulinemic syndrome in chronic hepatitis patients were 2%, 0.8%, and 0%, respectively. In cirrhosis patients the prevalence was 4%, 8%, and 0%, respectively. No statistically significant differences were found between the two groups. During the follow-up only one patient for each group abruptly developed cryoglobulinemic syndrome, and none of the patients who showed signs of cryoglobulinemia developed the syndrome or showed signs of evolution of the disease.

CONCLUSIONS

Our data demonstrate that the presence of cryoglobulins and/or cryoglobulinemic syndrome in HCV-related liver disease is unusual, as is the occurrence of cryoglobulinemia over time in these patients. This leads us to think that HCV-related cryoglobulinemic syndrome and HCV-related liver disease are independent diseases. This supports new and indirect evidence for an independent and direct role of HCV in liver and blood disorders.

Primary lymphoma of the liver: clinical-pathological features and relationship with HCV infection in French patients

Primary lymphoma of the liver (PLL) is rare. In some cases, the hepatic lymphoma has been diagnosed in patients who were infected by the hepatitis C virus (HCV). It has been suggested that HCV plays a role in the pathogenesis of lymphoma. The aim of our multicentric retrospective study was to assess the characteristics of PLL and to determine the prevalence of HCV infection in PLL. Thirty-one immunocompetent patients (anti-human immunodeficiency virus, anti-human T-cell leukemia/lymphoma virus negative, no history of allograft) with PLL fulfilled the entire selection criteria. The liver biopsy specimens were reassessed by the same pathologist. The non-Hodgkin's lymphomas were classified according to the World Health Organization classification. Blood samples were tested in 28 patients for antibodies to HCV, and HCV RNA was detected by reverse transcription polymerase chain reaction. In the majority of cases, the clinical, biologic, and radiologic data were nonspecific. Twenty-seven of 31 patients presented a B-cell lymphoma corresponding to the centroblastic morphologic variant of a diffuse, large B-cell lymphoma (22 cases), a Burkitt's lymphoma (1 case), an extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type (3 cases), and unclassified, small B-cell lymphoma (1 case). The 4 other cases were T-cell lymphomas. The prevalence of HCV infection was 21% (6 of 28 cases). All of these patients were positive for HCV RNA by polymerase chain reaction in blood. Most of the HCV-infected patients presented a high-grade, B-cell type lymphoma. In conclusion, our study confirms the rarity of PLL and demonstrates an increased prevalence of HCV infection.